Fact pattern: A pro se inventor drafted and filed a USProv, and then drafted and filed PCT filed with priority to the USProv, but without a statement incorporating the USProv by reference. He then entered the national phase in the US. Now it has been finally rejected due to the claims not being supported by the spec. Now he wants to bring in the missing support from the USProv.

I'm thinking 37 CFR 1.57a says that the priority document is considered incorporated by reference owing to the PCT priority claim, and 1.57b lets him amend the application to explicitly include the incorporation by reference statement. But 1) 1.57a says that he can only bring in "inadvertantly omitted" material, and 2) 1.57c says that "essential material" can only be brought in from a U.S. Patent or a "U.S. patent application publication". Regarding the latter point, the USProv became publicly available when the PCT published (e.g., via patentscope), but does this count as a "U.S. patent application publication"? I can't really say.

Alternatively, would he be able to file a CIP that includes the material from the USProv? I can't remember why not, other than to say that if he could, why did they bother to invent 1.57a if it could just as easily be remedied by filing a CIP?